


A Harmonious Hook-Up

by HaMandCheezIts



Category: Back to the Future (Movies)
Genre: 1985, Alternate Universe (kind of), Bisexual Male Character, Boys Kissing, Consensual Underage Sex, Erections, First Time Blow Jobs, Fondling, Friends to Lovers, Gay Sex, Horny Teenagers, Lone Pine timeline, M/M, Male Slash, Masturbation, One Shot, Oral Sex, Original Male Character(s) - Freeform, Partial Nudity, Pinheads, Plot What Plot/Porn Without Plot, Post-Break Up, Pre Time Travel, Relationship(s), Secret Crush, Sixteen/Seventeen so basically underage, Slash, Spit As Lube, Underage Sex, Wet & Messy, band practice
Language: English
Status: Completed
Published: 2020-09-06
Updated: 2020-09-06
Packaged: 2021-03-06 23:27:42
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,760
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26317165
Author URL: https://archiveofourown.org/users/HaMandCheezIts/pseuds/HaMandCheezIts
Summary: Band practice isn't the only thing that happens in the basement.
Relationships: Marty McFly/Original Male Character(s)
Comments: 2
Kudos: 15





	A Harmonious Hook-Up

**Author's Note:**

> I just wanted to try my hand at this, haven't done an Explicit or a Porn-Without-Plot story before (so be kind). Sorry that the hook-up individual is an original character (although I've established him - and his nickname for Marty - in my earlier stories). I've already done a "Doc and Marty" physical relationship fic, so I thought I'd try something different. 
> 
> As Marty is sixteen (for another week) and Isaac is relatively the same age, this gets an "Underage" warning. This is also an AU of a sort: it's a "Lone Pine" timeline fic, but before the time travel - so this Marty has a fancy truck and decent parents and siblings; he's the "other" Marty that the Marty we know and love replaces when he returns from 1955. 
> 
> **Disclaimer:** I do not own _Back to the Future,_ Doctor Emmett L. Brown, Marty McFly (or any of his family members), or Jennifer Parker. I have created several original characters that are in this story. 
> 
> I am writing for fun and feedback, not for profit.
> 
> -ck

_I'm standing on my last leg, I've just spent my last dime  
But other than that I'm doin' fine  
Living on the road ain't all it's cut out to be._

_Writing my songs in an all-night dine  
Drinking lukewarm coffee just to stay alive  
But I gotta keep on workin' - nothing's for free._

_Can't stop thinkin' of ya  
Been dreamin' about your touch  
The only thing that's on my mind is  
I'm comin' back to stay this time._

Excerpt from "Comin' Back to Stay this Time" by The Pinheads (written by M. McFly)

**Wednesday, June 5th, 1985**

**3:41 P.M.**

**Hill Valley, California**

When Marty McFly came in late (a third time) on his vocals for “Comin’ Back to Stay this Time,” which _he’d_ written – and when he mis-sang his own lyrics, Pete Grande called it. “All right, guys, let’s wrap it up,” he said to the other Pinheads, an obvious note of irritation in his voice.

“I’m sorry, guys,” Marty said tonelessly, lifting his guitar and strap over his head so he could place the instrument on a nearby stand. “I just can’t concentrate.”

“We know.” Paul had removed his bass guitar as well, and after setting it aside, he patted Marty consolingly on the back. “It’s a bitch.“ 

Marty stared in disbelief at his closest friend, and Paul quickly raised his hands in deflection of the acid glare. “No, I didn’t say ‘she’ – no, she’s not – I said _it’s_ a bitch! The _situation_ is a bitch! I wouldn’t say that about Jennifer!”

“Don’t baby him, Hardy,” Pete said. “He’s acting like he’s the only person who ever broke up with somebody.” He looked sharply at Marty. “It was your fucking idea to try out for the Solstice Festival, and now you’re gonna sabotage the whole audition, because you’re too busy moping to play a song all the way through.”

Marty straightened up to his full height, puffing his chest out. “I’ll be ready,” he replied. “But Jenn _just_ broke up with me, give me a goddamned minute, willlya?!” He advanced menacingly on the keyboardist.

“ _Just_ broke up with you – that was over a week ago.”

“Yeah, after being together for two and a half years! Maybe if you’d ever actually dated someone longer than a month, you’d know what this feels like!”

Marty and Pete were almost face to face now, and it was possible that soon one of them would know what a punch in the nose felt like. Isaac jumped up from behind the drums, running to put himself in between Marty and Pete; Paul was attempting to do the same. “Stop it, guys, this isn’t helping anybody!” Isaac shouted. He shoved Pete away from Marty, although not too roughly – the band members were all friends, after all. “Pete, why don’t you go? Just leave your stuff here – we’ll all try again tomorrow, how’s that sound? Okay, guys?”

Paul and Marty agreed, although Marty’s “sure” was unenthusiastic, at best – at worst, it was a downright lie.

“Pete?” Isaac prompted. “Tomorrow?”

With a grumble of acquiescence, Pete turned away, heading for the stairs that led to the basement’s outdoor access. “Wait, I rode with him,” Paul said, quickly moving to pick up his guitar and fumbling it into its case. “Pete, wait for me, man!” Paul paused to look carefully at his best friend. “You gonna be all right, Marty? Are you okay to drive home?”

“It’s not like he’s drunk or something!” Pete yelled down the stairs. “He just broke up with his girlfriend!” 

“She broke up with me!” Marty shouted back.

“Just go, Paul, get him out of here,” Isaac said urgently, as Pete’s feet could be heard descending the stairs. “I’ll take care of Marty. Go!”

After a quick nod and a quicker half-hug with Marty (somewhat hampered by Paul‘s guitar), Paul ran up the stairs, pushed a still-grumbling Pete ahead of him, and they both exited the basement. Marty looked in the direction of the stairs, glanced at the crooked, dusty clock on the wall, and then dropped to sit on the second-hand couch across from the remaining instruments. He put his head in his hands and moaned despondently.

Isaac glanced up as he heard Pete’s truck start, and when the engine could be heard moving away, he gazed at Marty. The drummer then slowly made his way to the couch and eased down next to his friend.

“You okay, Mac?”

Marty involuntarily winced, and Isaac hissed softly. “Sorry, Marty, I know you don’t like that.”

Marty waved a hand, but didn’t respond to Isaac’s apology for the nickname, or to his earlier question. He kept his head lowered, sighing deeply.

“Marty. . . If you want to talk, I'm here. You don’t have to go home right away. My mom won’t be home from work for another hour. And even if you’re still here when she gets home, she won’t care. You could stick around, have supper with us. . . “

Marty finally lifted his head. “Thanks, but no. My mom’s been worried about me since Jennifer broke things off, which means she’s been feeding me non-stop. Or trying to. I haven’t had much of an appetite.”

“You know. . . Pete might have been kind of right.” When Marty looked indignant, Isaac shrugged. “You’re not the only person who’s ever gone through a breakup. It’s not the end of the world.”

“But I just don’t get it!” Marty lamented. “Things were going great – we used to say we were 'meant to be'! This came out of nowhere, her saying she 'needed space,' and what the hell does that even mean?” He looked desperately at Isaac. “Has Sherri ever said anything like that to you?”

“Not in those words." Isaac shrugged again. "We aren’t exactly hot and heavy right now, anyway." When Marty looked distressed, Isaac waved him off. "It's just 'cause we're gonna be apart for a while - she left on that cross-country vacation with her family, remember?"

"Oh, yeah. Right." Marty looked aside, not meeting his friend's eyes. He'd been so preoccupied by his breakup with Jennifer, he'd honestly forgotten that Sherri had left a few days ago.

Isaac smiled at Marty's reaction. "Well, she won't be back until July, so we're kind of cooling it. We both knew that something could happen while she was gone – on my end or hers.”

Marty goggled at the drummer. “She didn’t have a problem with that? Knowing that you might meet someone while she was gone?” He knew Isaac and Sherri had only been together a few months, but _still._

Isaac looked away, running his hands nervously over his knees. “Well, _she_ might meet somebody. For me, it was more like hooking-up with someone I already know. Sherri and I talked before she left, and I told her how I felt, that I've always kinda liked this person. . . She was okay with it.”

“I can’t believe that,” Marty said. “She gave you permission?”

Isaac smiled softly. “Sherri’s great. She gets me. And I couldn’t tell her she wasn’t allowed to meet anyone, when she said she was okay with my thing.”

"Weird." Marty shook his head, temporarily distracted from his own woes. _I wonder if he's talking about getting with Jorie, his girlfriend before Sherri._ Then his face creased in fresh worry, as he remembered that Jennifer had been with Grant before _they_ had started dating. “I hope that’s not what’s going on with Jenn," he bemoaned. "That she has feelings for someone else, or met someone – that would kill me. There’s no way I’ll get her back if that happened.”

Isaac clicked his tongue. “'Get her back,'" he muttered. "C’mon, Marty, Jennifer’s not the only person in the world. You can’t just rate yourself on your relationship with her. You probably didn’t realize it, because you had love blinders on, but there’s other people who think you’re pretty great.” As Isaac spoke, he sidled closer to Marty, until there was hardly any space between them. “Jennifer’s not the only one who's ever looked at you.“

Marty had been stressing over his new concern of Jennifer possibly having eyes for another, and so hadn’t been completely paying attention to Isaac’s new position – until he felt the other boy’s thigh rub purposefully against his. Marty automatically glanced down at the touch, and when he looked back up, Isaac leaned in and pressed a soft, long kiss on his mouth. One of Isaac's hands squeezed Marty's knee, while the other moved around to caress his neck, his fingers tickling at the nape exactly like Jenn would do and Isaac's tongue was poking at his lips and _fuck_ –

Marty broke away, moving quickly to the far end of the couch, staring with wide eyes. His lifted a shaking hand and touched his lips, which were still burning from the kiss.

Isaac stared back, but his eyes were half-slits, and there was a small grin on his face. A small, sultry, _knowing_ grin.

“Jesus,” Marty whispered. “Isaac. Jesus.” It was all he could manage to say. _**I'm** the "someone" he already knows!_

Isaac’s grin widened. “You know how long I’ve wanted to do that, Marty? Practically since you joined the band. Listening to you sing, watching you play. . . “ He moved closer again; Marty, paralyzed by a speechless astonishment, was unable to move. He watched with silent apprehension and slight dizziness as Isaac reached out a hand. The drummer took one of Marty’s hands in his own; the touch was gentle, reverent. “The way your fingers make those strings sing, _these_ fingers. . .” Isaac lifted Marty’s hand and kissed it; Marty inhaled in shock. Then, separating the fingers, Isaac brought them to his mouth and began to suck on them one by one, running his tongue along each digit. Marty let out a soft whimper, feeling an odd tingling in his chest and stomach . . . and a definite flush of heat, spreading below his belly.

 _What the hell?_ Marty didn’t understand the familiar yet foreign sensations going on inside of him, the betrayal of his body. He’d only ever felt this excited by Jennifer, _never_ about anyone else, girl . . . or boy. He’d never even considered that possibility, never found any guy attractive – well, not personally. Sure, he’d noticed certain guys who were good-looking, merely in a factual capacity; who hadn't? It didn't have to _mean_ anything . . . There was Dave’s buddy Tyler, who was muscular yet slender, toned and athletic, and who had the longest eyelashes Marty had ever seen on a guy. And Paul’s older brother, who Marty had known almost ten years . . . and had watched transform from an awkward nerd to a chiseled Lothario. Hell, even Doc was sexy, with his wide grin and chocolate-brown eyes, his genius mind and electric, contagious energy. The damned brightness of the guy.

_But yeah, I’ve just **noticed** them. I've never acted on anything, I wouldn't act on anything. I **wouldn't.** Because I’m not – not – _

_Not . . . what?_

He thought about how Doc's brightness had blinded him years ago, probably right around when he'd started his "official" assistant job. Thought about how that shine sometimes still dazzled him, even after he'd begun dating Jennifer. Thought about how he'd done his best to ignore that enamored feeling, because Doc was his _best friend,_ damn it, and Marty wasn't - wasn't -

_Gay? Bisexual?_

“W-wait. . . Stop.” Marty slowly pulled his hand back, unexpectedly trembling. He looked at the slick saliva on his fingers, and fought the urge to wipe them off, worried that it would offend Isaac. _Why should I care about offending him? No one asked him to hit on me! I never sent him any signals!_

_Did I?_

Marty attempted to ignore his contrary thoughts, although it proved difficult as his pulse was pounding in his ears. He drew in a shuddering breath. "I don’t feel that way about you, Isaac," he said. The words sounded right, but they felt forced, and tasted false. 

Isaac put his hands on his hips, setting his arms akimbo. He looked at Marty with a no-nonsense expression that was somehow both stern and seductive. “Oh, yeah? Give it up, McFly.” He gestured at Marty’s groin, and at the obvious bulge apparent even through the denim material. “Tell your dick you don’t feel that way about me.”

“Shit, Isaac!” Knowing he was caught, Marty instantly blushed; his hands flew up to rake through his hair. “This – this is nuts! I like girls! You know I’m with Jennifer!”

Isaac leaned in again. “Not at the moment. Who knows what will happen with her? Who knows what will happen with me and Sherri? But I say we forget about them right now. Right now is about us.”

The way that Isaac was moving in, intently and persistently, meant Marty’s only option was to lay back. He stared up at the auburn-haired boy hovering over him, distractedly appreciating his infuriatingly good looks - perfect nose, flawless skin, slightly crooked teeth. Full, moist lips. There was a faint sheen of perspiration above Isaac's upper lip, and the drummer shot out his tongue to lick at the sweat. _Did he do that deliberately?_ Marty wondered, his stomach leaping at the brief sight of the pink tongue. A pleasurable warmth was overwhelming him.

Marty considered twisting off the couch, to escape onto the floor. Or maybe lifting his knee, to slam it right between Isaac’s legs. He thought about raising his hand, to slug Isaac in that beautiful mouth.

Marty didn’t twist away, and he didn’t knee Isaac in the nuts. He did raise his hand – and grasped Isaac by the neck. Then he impulsively pulled the boy’s head down and kissed him so hard their teeth clinked together. Isaac made a surprised “mmf” sound, and then Marty’s tongue was in his mouth and it was all the drummer could do to not cry out in joy.

When they both needed to stop for air, Isaac lifted himself up, bracing his arms on either side of a breathless Marty. “Damn, you’re a good kisser," he said softly, awed.

 _Never had any complaints from Jennifer,_ Marty thought smugly, but not wanting to think about his girlfriend _(if she still **is** my girlfriend)_ and what she might say about this - development - if she knew, all he said in reply was, “Ditto.” Then Marty rose up and grabbed Isaac, again pulling him down. They shared another bruising, tongue-thrusting kiss, Marty's hands running over Isaac's shoulders while Isaac's fingers tangled in the guitarist's hair.

Marty decided he also didn't want to think about how Isaac was a better kisser than Jennifer. Every nerve in his body was on fire. His heart was thundering, the beats traveling through him down to his fingers and toes . . . and other extremities. He became painfully aware of the arousal Isaac had previously pointed out. Suddenly realizing that he could feel a hardness against him during the kiss, Marty pulled away, then jerked his head fractionally at Isaac’s waist. “It looks like your dick is showing its feelings, too.”

Isaac grinned. “Damn straight.” He adjusted his position, resting on his knees straddling Marty's legs, and started to unbuckle his belt. “You don’t know how many times I’ve jerked off to you. Listening to the crappy recordings we make, the times you’d break and laugh. . .” He leaned in, placing a hot kiss on Marty’s neck, eliciting a gasp from the guitarist. Straightening, Isaac went back to his belt, removing it and tossing it to the floor. Next the drummer unsnapped his pants, wiggling needily against Marty. Then he reached for the fly of Marty’s jeans.

Marty shifted, turning and struggling away from Isaac's eager hands. “Isaac, stop, I don’t – I don’t think I . . . “

Isaac halted, his face falling. “Marty, the way you kissed me, I thought – I thought you wanted this.“

“I don’t know, Isaac, just – “ Marty scrambled up onto his elbows. “I don't know what I want. I’ve never done anything like this before.”

Isaac smiled crookedly. “You think I have?” At Marty’s raised eyebrows, Isaac shook his head. “No, not with a guy. But I figure it can’t be too different than with a girl, right?”

Marty gave a short laugh, amused yet interested. “How do you think that? We’ve got different parts, you know."

Isaac smiled again, and _damn_ but how did Marty not notice before how cute that crooked smile was? “I know what Sherri's done to me, with just her hands and her mouth, and we've got those.” He reached out again to Marty’s crotch, but didn’t try to unzip his pants; instead he palmed his friend’s cock through his jeans. “See? Hands.”

Marty fell back off his elbows, instinctively grinding against the enticing rubbing of Isaac’s hand. _Hands. Hands and mouths_. Was that so hard to imagine? Jennifer had done that to him, probably the same as what Sherri did to Isaac. He and Isaac could do that. They could figure it out.

And If Isaac did all of the work, it wouldn’t even be like Marty was cheating on Jennifer. Not _really._ Although, if he ended up "satisfying" Isaac. . .

 _Hell with it._ Jennifer was the one that had broken up with him, after all.

Marty began to unzip his fly, and Isaac, understanding the decision behind the motion, quickly finished undoing his own pants. He pushed his pants and underwear past his hips and down his thighs, enough to free his erect penis. At the same time, Marty was wriggling out of his jeans and briefs, lifting his hips up so he could push the clothing down into a bunch by his knees. The two half-naked boys then gazed at one another’s exposed hard-ons, Marty panting from his minor exertion and Isaac working his mouth silently. Marty was fairly relieved to see that, although the drummer had a couple inches on him in height, Isaac wasn't much bigger than him where it counted. Marty moved a slow, cautious hand, reaching for the cock of the boy leaning over him. He ran his hand over Isaac's erection, grasping it for a few languid strokes. Then Marty circled a finger gingerly around the sensitive head, smearing the precum. Isaac groaned indulgently, writhing as his cock jolted under Marty's careful fondling. But then the drummer shook his head rapidly. "No. You. I want you." 

Isaac had lowered his head before Marty could disagree. He kissed the head of Marty’s cock, making the guitarist yelp softly. Then, after suckling the head briefly, he bent lower, and starting at the base, he licked one long streak up the shaft. Marty jerked and muttered, going nearly rigid and gritting his teeth. Isaac drew back, checking his friend’s expression. Marty nodded dumbly. “’sokay,” he forced out. With a quick grin, Isaac went back to his ministrations, only this time he closed his mouth fully around Marty’s dick. Isaac expertly sucked, licked, and explored, bobbing his head as he brought Marty's cock in and out of his hot, wet, mouth, each time going farther and deeper. Marty gripped the edge of the couch, whining as his body convulsed in ecstasy. Isaac had never done this before? This was amazing, astounding, electrifying, overwhelming – he already felt so full, so ready to burst, so -

“Y – you – but what – what about – “ Marty puffed, causing Isaac to momentarily pull off his cock. Too worked up to speak clearly, Marty made an awkward gesture at Isaac’s dripping hardness. It hardly felt fair, that Isaac could make him feel like this, like Jennifer _never_ had, and yet Marty couldn't reciprocate. Wasn't even sure if he'd have the energy or ability to fully reciprocate. 

“I got it,” Isaac murmured. “Told ya, I’ve jerked off to you a lot. And now I've got the real thing.” Isaac spat into his palm, then took himself in hand and began to stroke in earnest. "I can do both.” Leaning in again, one hand grasping Marty's hip and the moistened hand fisting his own thick cock, Isaac again applied his mouth to Marty.

It was forever, it was an instant. It was exhilarating, it was exhausting. Marty tried to watch, wanting to see Isaac's flushed, sweaty face as the boy nearly choked himself in his mission, but Marty's eyes were rolling back in his head; all he could see were random stars and sparks, increasing in frequency as he neared climax. When Marty felt the familiar squeeze of muscle and knew he couldn’t hold back much longer, he panicked, even in his rapture. He didn't know how Isaac might react to a mouthful of cum; the one time Marty had ejaculated in Jennifer's mouth, she had been so unnerved that she'd reverted back to modest over-the-underwear petting when they'd gotten intimate. And _that_ blow job had been "normal" - at least, it had been his girlfriend sucking him, not a guy he considered one of his closest friends.

“Get – _stop_ – let me – " he pushed against Isaac’s head, beating on his shoulders in between grunting and thrusting his hips. “Gonna _cuuUU **UMM!!!"**_

Isaac pulled off at the last possible second, and Marty scrabbled to grab himself and aim his spurts. He was able to narrowly avoid exploding into Isaac's mouth - his spunk hit the boy's chin instead, and striped down his shirt. Marty cried out intelligibly through the orgasm, although an occasional curse accompanied his cries. And as Marty was wheezing and shaking and coming down, his partially-erect cock still dribbling, Isaac suddenly shouted – his masturbating having been wildly successful. His jizz shot out onto Marty’s groin and thighs, but as Isaac was too occupied to be precise, cum also spattered onto Marty’s stomach and chest, ruining his shirt as well. “Fuck. Fuck,” Isaac panted, fighting to breathe through the aftershocks. “Guess. . . we shoulda . . . undressed.”

“Yeah.” Marty nodded jerkily. “And your face, man. Damn, I’m sorry.”

Isaac lifted a hand, irreverently mopping the semen off his chin, then wiping his soiled hand onto his shirt. “Hell, it’s already wrecked.”

The two began to laugh, and Isaac dropped down on Marty, enveloping his friend in an embrace. The two bandmates' sticky, wet groins pressed together, causing their waning erections to meet pleasurably. “Man," Isaac murmured, "that was . . . that was _perfect_.” He kissed Marty’s nose, and both corners of his mouth. “Thank you, Marty.”

Marty lifted his head to kiss Isaac, directly on the mouth and with a probing tongue. He pulled out of the kiss slowly, momentarily trapping Isaac’s lower lip between his teeth. Then Marty let his head fall against the back of the couch, and he grinned up contentedly at his friend.

“Call me Mac.”

**_END_ **

**Author's Note:**

> The topic of Jennifer “needing space” from Marty at the end of their junior year is discussed in my story ["The Resulting Present of Respective Pasts."](https://archiveofourown.org/works/21206864) Doc mentions the event, but Marty claims it never occurred. As I wrote in my top notes, the breakup happens in the Lone Pine timeline, which is the only one Emmett recalls (after Marty's original time travel to 1955); Marty's knowledge of the the altered timeline is sketchy, so he doesn't remember Jennifer breaking up with him until Doc reminds him of it. 
> 
> So who knows - maybe the dalliance between Isaac and Marty did happen, but was conveniently "forgotten" when Marty and Jennifer reunited.


End file.
